The present invention generally relates to semiconductor integrated circuits, and more particularly, to multilayer image transfer process employing a TiOxNy hard mask layer and structures for effecting the same.
A trilayer lithography process is an exemplary multilayer patterning scheme known in the art that employs organic/inorganic/organic layers to produce sub ground rule (less than 40 nm) of various structure and features such as gate structures. An organic material layer such as an amorphous carbon layer is often used in order to transfer a composite image of two independent images. An underlying, ultrathin silicon containing layer acts as a hardmask during the etch transfer step. The third layer is typically an organic film. Trilayer processing thus offers the opportunity for a significant reduction in photoresist film thickness and provides a potential solution to the familiar aspect ratio problem encountered during wet development of 193-nm single layer resists.